Preliminary Research Of Reproductive Biology Of Juglans Mandshurica Maxim.heterodichogamy

Juglans mandshurica Maxim.belongs to Juglandaceae of Juglans.It is a heterodichogamy plant.Its dichogamous can affect the sexual reproduction process such as flowering and pollination directly,even affect the yield and quality of fruit.Protogyny and protandry were research objects in this study,who are two main mating types of Juglans mandshurica.The aim is to lay a foundation for the study of the differentiation mechanism of male and female heteromorphic sex of Juglans mandshurica in the aspects of morphology,anatomy and physiology.We investigated the flowering phenological characteristics of two main mating types in detail.Morphological and anatomical observations were made on the differentiation of two types of male and female flower buds,and the study analyzed the law of material metabolism in the body during the process of differentiation.The following conclusions are drawn from the researches:1.The flowering phenology of two main mating types of Juglans Mandshurica was observed for 3 consecutive years.The conclusion is that: in the eastern of Liaoning,the SAP begins to flow in early and mid-March,and the flowering period is from the end of April to the end of May.Flower buds begin to sprout at the end of April and the beginning of May.Female flower buds of protogyny sprouted first.But male flower buds of protandry sprouted first.And then blossomed in mid-May.When the male sequence of protandry is matured powder,the female flowers of protogyny opened in pollination period.When the male sequence of protogyny is matured powder,the female flowers of protandry opened in pollination period.Between different types of male and female florescence can overlap 3-5d,but the same type has different florescence,which can avoid self-pollination effectively.After a week of pollination,the female flowers begin to bear fruit.Based on the phenological observation for 3 consecutive years,the sex differentiation of sexual dimorphism of Juglans Mandshurica was stable,and the flowering period of Juglans Mandshurica could be advanced or delayed several days each year because of the different climate.2.The morphology,cytology and anatomy of male and female flower buds of male and female pioneer type of Juglans Mandshurica was observed by scanning electron microscope.The developmental stages of male flower buds can be divided into: undifferentiated stage of male flower buds,germinating stage of male flower buds,stamen formation stage,stamen development stage,anther formation stage and pollen grain formation stage.The developmental stages of female flower buds are divided into: undifferentiated stage of female flower buds,germinating stage of female flower buds,involucral primordium development stage,pistil primordium formation and development stage,ovule development stage and ovary expansion stage.The differentiation and development of the female flower buds of protogyny is always earlier than protandry.The differentiation and development of male flower buds of protandry is always earlier than protogyny,the process of differentiation is identical.3.The pollen morphology of Juglans mandshurica is oblate,which is known by scanning electron microscope.Pollen has a thin outer wall on one side,and 8-16 germinating holes on the pollen surface.The polar axis length of pollen was about 1.93?m,and the equatorial axis length was about 33.17?m.The ratio of polar axis to equatorial axis P/E was 1.26.It was found that the benzidine method was more suitable for the determination of pollen viability,and the viability and germination rate were highest when the pollens were stored at 4?.Pollen germination was determined by culture medium,and the optimum medium ratio was 2% AGAR +0.05% boric acid +15% sucrose,and the pollen germination rate was 94.03%.4.Based on the analysis of physiological metabolites flower buds in protogyny and protandry,we found that the changes of physiological metabolites were closely related to the morphological development of flower buds.The content of soluble protein in two types of male flower buds reached the peak during the morphological differentiation,which was the energy storage of anther powder.However the soluble protein content of female flower buds reached a peak at the stage of morphological differentiation.With the continued development of flower bud,the content of protein began to decrease.This indicated that the development of female flower bud into female flower needs to consume a lot of protein to satisfy its growth.And the content of protein reached the peak again at the flowering stage,which meets the need of pollination.When the vegetative growth ended period and enter the physiological differentiation period,the content of soluble sugar in the male flower buds of the two types reached the peak,and then decreased gradually with the elongation of male inflorescence and the formation of anthers.Its showed that the accumulation of soluble sugar promoted the development of male flowers.While there were two peaks of soluble sugar changes in the buds of female flowers.The first peak appeared when the flower buds began to sprout at the beginning of physiological differentiation,the second peak occurred at anthesis and then decreased with the end of pollination.The content of soluble starch in male flower buds reached its peak at the stage of physiological differentiation(germination),and decreased after the stage of morphological differentiation.While the content of female flower buds reached its peak at the early stage of flowering,the results showed that the accumulation of soluble starch could promote the formation of female flowers.